There are techniques employing, for production with good yield such as of a polarization film or phase difference film having an orientation axis tilted at 45 degrees, a sheet or film clipping stretcher adapted to grip right and left sides edges of a polymer film (as sheet or film) by pluralities of clips, respectively, moving those clips in a longitudinal direction of the polymer film, giving tensile forces to the polymer film in an oblique direction to implement an oblique stretch.
For oblique stretch by a sheet or film clipping stretcher having, even clip pitches, it is necessary to provide clips on one side with a delay (one-sided delay) identical in dimension to a stretch exit width of clips on the other side, between sheet or film grip and release positions of clips, to provide a sheet or film with a stretch component in an oblique direction tilted relative to a travel direction of the sheet or film.
In this respect, there are sheet or film clipping stretchers disclosed in patent documents 1 and 2, where they provide clip travel locus lengths between sheet or film grip and release positions of clips, with a difference between right clip and left clip to give a one-sided delay Further, there is a sheet or film clipping stretcher disclosed in patent document 3, where it provides a difference between travel speed of right clip and travel speed of left clip to give a one-sided delay.    Patent document 1: Japanese Patent Application Laid-Open Publication No, 2002-86554    Patent document 2: Japanese Patent Application Laid-Open Publication No. 2004-325561    Patent document 3: Japanese Patent Application Laid-Open Publication No. 2002-22944